Hi there, give me a couple of hours. I'll put together a tutorial that will handle that for you. First a few questions/suggestion.
1) Are you authenticating the player? or they just type in any name. In the latter case each player can have infinite names.
2) Server-side storage. I strongly suggest MySQL database just in case you end of having millions
3) Front-end are you going to display the scores in game or online or both?
Please answer back quickly if possible since I am starting the project now.